Research On SMC System With Rapid Initation And High Filling

Sheet molding composites(SMC)is the importand polymeric composites and most widely used in automotive industry.At present,the cure system and high cost of SMC,which are the key links to limit the domestic rapid development donnot need the batch process.It is required to do the deeply theory and experiment research on the cure system and filling system.This paper studies the kinetic model of single initiating system and double initiating system of SMC.The isothermal kinetic model and nonisothermal kinetic model are proposed by test isothermal differential scanning calorimetry(DSC)curve and nonisothermal DSC curve.The relation of double initiation agent proportion and the time parameters t_z and t_m of the cure process can be pre-estimate by the isothermal kinetic model.The relation of the temperature of double initiation system and the rate of conversion can be calculated.The temperature parameters T_onset,T_p and T_z can be pre-estimate by the nonisothermal kinetic model.The effects of the rapid initiating system to the properties of SMC are studied,with the TBPB/TBPO and DBPC/TBPO composite initiating system,the shelf life,the exothermic peak and cure time of the four type unsaturated polyesters resins P17,P18,FL9508,FL9506 descend with the low temperature initiating agent increase.When the proportion of the high temperature initiating agent to the low temperature initiating agent is 80:20,The effect of the low temperature initiating agent to the shelf life isnot noticeable.With the rapid initiating system,the cure time of SMC molding compress is significant shorten,the properties of products,such as glossiness,agree of cure,bending strength and hardness is good.The graduation of filler and the modification of filler surface are studies in this paper.According to the theory of double peak accumulation,the closet packing composite filler is acquired when the type filler proportion is B5:Cb=8:2.The pore volume friction of the closet packing composite filler is 41.8%and less than the other composite fillers.The short-range and long-range wavinesses of products with the closet packing composite filler is less than the products with single fillers,and surface qualities of products reach the A-class lever.In the product of SMC,the effect of the same dispersant agent to the different type of filler is different.The effect of BYK-W9010 to calcium carbonate is better than to aluminum hydroxide,the assistant of BELGEN is opposite,the assistant of NOYI is same to calcium carbonate and aluminum hydroxide.The viscosity of resin paste can be notable decreased by coupling agent.The KG-SMC combined the rapid initiating system and high filling technology, its molding time is shorten 40%,the filler adding increase 30%,impact ductility increase 11.8%.The waviness of KG-SMC is better than PT-SMC and surface qualities of products reach the A-class lever.The success development of the advanced SMC system with rapid initiating system and high filling show the theory of composite initiating system and double peak accumulation are work for improving the product efficiency and quality of SMC procducts,reducing cost.The batch products supply is realized by the advanced SMC system in this paper.